Starting-box and controller for electric motors.



O O H O 2 hm e F d e t n e t a P. B K A L B on F 8 5 3 4 6 O. N

STARTING BOX AND CONTROLLER FOR ELECTRIC MOTORS.

(Application filed Dec. 8, 1899.)

2 Sheets-Sheet I, v

(No Model.)

No. 643,758. Patented Feb. 20, I900. F. R. BLAKE.

STARTING BOX AND CONTROLLER FOR ELECTRIC MOTORS.

(Application filed Dec. 8, 1899.)

(No Model.) 2 Shaets$heet 2 UJHUFESEES! UNITED STATES PATENT OFFICE.

FRANK R. BLAKE, OF BOSTON, MASSACHUSETTS.

STARTING-BOX AND CONTROLLER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 643,758, dated February 20, 1900.

Application filed December 8,1899. Serial No. 739,699, (No model.)

electric motors employed for operating elevators. Such an apparatus usually comprises a resistance-box and a switch for the circuit of the motor; and my invention consists in novel means of cutting out the resistances, also in a novel form of switch for operating the circuit of the motor, and also in connections whereby the means employed for cutting out the resistances shall be operated by said novel form of switch, all as will be hereinafter more particularly set forth.

Figure 1 shows in front elevation a starting-box and controller for electric motors embodying this invention. Fig. 2 is an edge view and partial section of the switch-arm which controls the circuit of the electric motor. Fig. 3 is a side elevation of the starting-box and controller shown in Fig. 1. Fig. A is a detail of an escapement mechanism for controlling the movement of a rack-bar bearing the contact-fingers which cooperate with the plates of the resistance-box, and Fig. 5 an enlarged side view of a portion of the switch-arm of the switch which controls the circuit of the motor.

The box or case A is of any suitable size and shape and contains any usual resistance-coils, which it is not deemed necessary to herein illustrate in detail. a represents the plates connected with said resistance-coils and which are herein referred to as resistance-plates. There will beany number of resistance-plates provided, as may be desired, and they will be made of any suitable shape and size and disposed relatively to each other in any desirable manner.

Two pairs of contact-fingers I) Z) a c are provided which. are adapted to cooperate with said resistance-plates, they being herein shown as separately pivoted at 2 to a crossbar d, which is secured to a vertically-dis posed rack-bar e, which is made of any suitable length and provided with suitable guides on the box A, by which its up-and-down movements may be guided. The pivoted con tact-fingers have suitable projections or extensions, to the extremities of which spiral springs b are connected, the opposite ends of said springs being connected to the said cross-bar cl or to any other fixed support. The springs I) serve to press the contact-fingers into engagement with the resistanceplates, holding them firmly yet yieldingly in contact therewith. The rack-bar c has attached to it a suitable weight 6, by means of which it will be caused to descend when permitted so to do. The descending movement of the rack-bar c is retarded to a certain extent in order that the several resistance-plates may be successively connected slowly, and as a simple and efficient form of retarding device by which this result may be accomplished I have provided an escapement mechanism, consisting of a pinion 6 which is adapted to be engaged by the teeth of the rack-bar e, a ratchet-wheel 6 secured to the shaft of said pinion 6 a pawl 6 which is engaged by said ratchet wheel, a toothed wheel 8 bearing .said pawl, loosely mounted on the shaft which served that such movement of the rack-bar is positive and liability of stopping at any intermediate point is reduced to the minimum.

The rack-bar c has secured to it, preferably adj ustably, a rearwardly-extendcd projection or stud f, the position of which on the rack bar may be regulated by the adjusting-screw f, and a lever is provided for engaging said projection fto lift the rack-bar and its attached weight to its most elevated position and hold it in such position. The switcharm 9 of the circuit-switch of the motor, to be described, is employed as the actuatinglever for engaging the projection f. The switch-arm g is pivoted at g and operates the contact-brushes which cooperate with the contact-plates of the switch, and said arm g is connected by a link g with any usual sheave, which may be operated in any usual or suitable manner, so that whenever said switch-arm is turned on its pivot in one direction to operate the circuit of the motor the rack-bar 6 will be released and permitted and caused to descend by means of the weight, its descending movement being controlled and retarded more or less by the escapement mechanism, and wheneversaid switch-arm g is turned in theopposite direction said rackbar will be restored.

The switch-arm g is provided with two pairs of brushes, or it may be with two brushes only, adapted to cooperate with concentrically-arranged segmental plates located beneath the arm. As herein shown, there are two pairs of segmental plates h h it, one pair for each side of the line, and a single insulated segmental plate 7t forms an extension of one of the segmental plates of each pair. These segmental plates are disposed concentrically and the switch-arm g pivoted between the respective pairs of plates.

The brushes borne by the switch-arm g each consists of a copper and a carbon block n n, loosely supported in a shell or case n of insulating material, set into ahole formed in the arm 9, and two such brushes are provided, one at each side of the pivot of said arm g, and said copper and carbon blocks in each shell or case n are located side by side and are adapted to be yieldingly pressed down onto the segmental plates by springs a the pressure of which is regulated by adjustingscrews n passing through threaded holes in plates 72", secured to the arm g.

I claim 1. Inadevice ofthekind described,the combination of a circuit-switch for the motor, a rack-bar bearing contact-fingers which cooperate with the resistance-plates, a retarding device for said rack-bar which controls its movement in one direction, a weight for moving said rack-bar in its retarded direction, and connections whereby said rack is moved in the opposite direction by the means employed for operating said circuit-switch, substantially as described.

2. Inadeviceofthekind described,thecombination of a circuit-switch for the motor, a rack-bar bearing contact-fingers which cooperate with the resistance-plates, a retarding device for said rack-bar Which controls its movement in one direction, a weight for moving said rack-barin its retarded direction, a

projection on said rack-bar adapted tobe engaged by the actuating-arm of said circuitswitch to be moved by said arm in the opposite direction, substantially as described.

In a device of the kind described,the combination of a circuit-switch for the motor, a rack-bar bearing contact-fingers which cooperate with the resistance-plates, escapement mechanism for retarding the movement of said rack-bar in one direction, a weight for moving said rack-bar in its retarded direction and connections whereby said rack-bar is moved in the opposite direction by the means employed for operating said circuit-switch, substantially as described.

at. In a device of the kind described, the 001m bination of a circuit-switch for the motor, a rack-bar bearing pivoted spring-pressed contact-fingers which cooperate with the resistance-plates, a retarding device for said rackbar which controls its movement in one direction, a weight for moving said rack-bar in its retarded direction, and connections whereby said rack-bar is moved in the opposite direction by the means employed for operating said circuit-switch,substantially as described.

5. In a device of the kind described,the combination of a circuit-switch for the motor comprising a number of concentrically-arranged segmental plates and a pivoted switch-arm bearing a number of contact-fingers adapted to cooperate with said segmental plates,means for turning said switch-arm on its pivot, a re= sistance-box having a number of plates, con tact-fingers cooperating with said plates, retarded operating mechanism for moving said contact-fingers over said plates in one direction slowly to cut out the resistances, and connections whereby said contact fingers are moved in the opposite direction and said retarded operating mechanism reset by said switch-arm, substantially as described.

6. In a device of the kind described,the com bination of a circuit-switch for the motor comprising a number of concentrically-arranged segmental plates, a' pivoted switch-arm bear ing a number of contact-fingers, means for turning said switch arm, a resistance -boX having a number of plates, contact-fingers cooperatin g with said plates, a rack-bar bearing said contact-fingers, escapement mechan ism for retarding the movement oi said rackbar in one direction, a weight for moving said rack-bar in its retarded direction, a projection on said rack-bar adapted to be engaged by said switch-arm for moving said rack-bar in the opposite direction, substantially as described.

7. In a device of the kind described, a circuitswitch for a motor comprising a number of contact-plates and a switch-arm bearing yieldingly-supported copper and carbon brushes located side by side and insulated from said switch-arm, substantially as described.

8. In a device of the kind described, a cir emit-switch for a motor comprising two pairs In testimony whereof I have signed my of segmental contact plates disposed con name to this specification in the presence of centrically, and a pivoted switch-arm beartwo subscribing Witnesses.

ing yieldiugly-supported copper and carbon FRANK R. BLAKE. 5 brushes located side by side and insulated Witnesses:

from said switch-arm, substantially as de- CHARLES SPRAGUE,

scribed. 13. J. NOYES. 

